Sintering device

ABSTRACT

A sintering device comprising a tray including a tray part in which metallic workpieces to be sintered (not represented here) are placed during the sintering operation and a base part in which the tray is located including gas-flowing holes and side wall extended upwardly from the edge of the upper surface of the base part, and a sintering chamber including side wall extended downwardly from the upper surface for covering the tray part and at least one gas flow passage between the inner surface thereof and outer surface of the side wall of the tray part; 
     wherein the tray part and base part are integrally formed; wherein the base part includes at the lower portion through holes in horizontal and longitudinal directions for gas inflowing and discharging, a hole at crossover point of the through holes for penetrating the center portion of the base plate and extended to the exterior, and wherein the lower end of the sinter chamber is disposed on the lowered and stepped surface of the base part and the stepped portion formed in the middle of the side wall of the sintering chamber is supported by the upper end of the side wall of the tray for allowing the gas to flow.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Korean Patent Application No.10-2016-0005990 filed Jan, 18, 2016, the entirety of the disclosure ofwhich is expressly incorporated herein by reference.

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not Applicable

BACKGROUND

The present invention relates to a sintering device, and moreparticularly to a sintering device comprising a cylindrical memberformed of titanium or titanium alloy to restrain oxidation of metallicworkpieces to be sintered in the sintering device. Furthermore, thepresent invention relates to a sintering device in which a tray may bearranged on a base plate in a chamber member in a gas-tight mannerwithout using any separate cover.

A conventional sintering device of the above-mentioned type comprises abase part, a tray placed on the base part, a cover for covering the trayaccommodating the sinter product and a tray chamber surrounding the trayand support plate.

As one example of such sintering device, U.S. patent applicationPublication No. 2013/0149186 discloses a structure that a tray isdisposed on a base plate with a space each other for flowing a gas.

U.S. patent application Publication No. 2014/0299195 discloses asintering device wherein a sintering material compartment member isplaced on a base part and a cover is arranged in the sintering materialcompartment member.

Also, the present applicant has suggested a sintering device in KoreanPatent Application No. 10-2015-0021470 filed on Feb. 12, 2015, which isincorporated herein for reference. As depicted in FIGS. 1 and 2, thesinter device comprises a tray 20 placed on the base plate 10, a covermember 30 for covering the tray and base plate. The cover member 30includes a lower end engaged with a stepped portion of the base plate 10and a middle stepped portion 32 supported on the upper end 23 of thetray 20. A recessed portion 12 is formed at the edge of the base plate10 for engaging the lower end 31 of the cover member 30. A hole for gasinflow and outflow is formed in the center portion of the base plate.The tray 20 is sealed by the base plate 10 and cover member 30. The tray20 includes a gas flow passage which comprises a ring-shaped protrusion21 formed at the bottom surface and recesses 22 in the ring-shapedprotrusion 21. The tray 20 is separated from the base plate 10 by theprotrusion 21.

However, there is a problem in the conventional sintering devicesmentioned above that an oxygen in the residual gas in the cavity formedby the cover 20 oxidize the sintering material in the cavity surroundedby the cover member 30 in the sintering process.

Furthermore, in the conventional sintering devices, a sintering chambershould be formed by a least two elements arranged on the base plate,thereby causing an increase of manufacturing costs and complexity ofstructure.

BRIEF SUMMARY

In order to accomplish the above-mentioned object, according to thepresent invention there is provided a sintering device comprising a trayincluding a tray part in which metallic workpieces to be sintered (notrepresented here) are placed during the sintering operation and a basepart in which the tray is located including gas-flowing holes and sidewall extended upwardly from the edge of the upper surface of the basepart, and a sintering chamber including side wall extended downwardlyfrom the upper surface for covering the tray part and at least one gasflow passage between the inner surface thereof and outer surface of theside wall of the tray part,

wherein the tray part and base part are integrally formed;

wherein the base part includes at the lower portion through holes inhorizontal and longitudinal directions for gas inflowing anddischarging, a hole at crossover point of the through holes forpenetrating the center portion of the base plate and extended to theexterior, and

wherein the lower end of the sinter chamber is disposed on the loweredand stepped surface of the base part and the stepped portion formed inthe middle of the side wall of the sintering chamber is supported by theupper end of the side wall of the tray for allowing the gas to flow.

According to the present invention, a cylindrical member for theprevention of oxidization may be disposed on the base part between theside walls of the tray part and sintering chamber to prevent the oxygencontacting the metallic workpiece.

The cylindrical member for the prevention of oxidization is preferablyformed in a sheet made from titanium or titanium allow.

The inner diameter of the sidewall of the sintering chamber is biggerthan the outer diameter of the side wall of the tray part to form acylindrical space as a gas flow passage between the side walls of thetray part and sintering chamber, and the cylindrical space iscommunicated with the through holes in horizontal and longitudinaldirections formed at the base part.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects, other features and advantages of the presentinvention will become more apparent by describing the preferredembodiments thereof with reference to the accompanying drawings, inwhich:

FIG. 1 is a cross-section view of the conventional exploded sinteringdevice in an exploded state which was filed by the present applicant;

FIG. 2 is a cross-section view of the assembled sintering device in FIG.1;

FIG. 3 is an exploded perspective view showing the improved sinteringdevice according to the preferred embodiment of the present invention,in which a tray part and a base part are integrally formed;

FIG. 4 is a partial cross section view of the sintering device in FIG.3;

FIG. 5 is a cross section view of the assembled sintering device in FIG.4; and

FIG. 6 is a cross section view of the variant embodiment of FIG. 5.

DETAILED DESCRIPTION

The present invention will be hereafter described in detail withreference to the accompanying drawings.

The sintering device according to the first embodiment of the presentinvention FIGS. 3, 4, 5 includes a tray comprising a tray part 330 and abase part 331 integrally formed therewith and a sintering chamber 340covering the tray part 330, the upper portion of the tray part 330 beingopened. That is, the tray part and the base part are different from atray and a base plate in the FIGS. 1 and 2 in that the tray part andbase part are integrally formed in one piece.

The tray part 330 is provided with a cylindrical side wall 332 formedupwardly on the bottom surface to form an inner space for accommodatingworkpieces therein and the base part 331 is formed with through holes334 in horizontal and longitudinal directions for gas inflowing anddischarging, and a hole 335 at crossover point of the through holes 334for penetrating the center portion of the base plate and extended to theexterior. Also, a lowered and stepped surface 333 is formed at the edgeportion of the base part 331.

The through holes 334 work as a gas passage for inflowing the argon gasand discharging the residual gas in the inner space of the tray part andthe hole 335 works as an gas inlet and an gas outlet connected to thegas supply and discharging means provided in the conventional sinteringdevice.

The sintering chamber 340 is mounted on the lowered and stepped surfaceof the base part for covering the tray part 330 and is provided with acylindrical side wall 342 formed in the downward direction and a steppedportion 341 in the middle of the side wall to increase the innerdiameter at the lower portion of the side wall.

When the sintering chamber 340 is mounted for covering the tray part330, the lower end of the side wall 342 seats on the stepped surface 333of the base part and the stepped portion 341 of the side wall 342 seatson the upper end of the side wall of the tray part 330, so that gas mayfollow through a fine gap between them.

The inner diameter of the side wall 342 of the sintering chamber 340 isbigger than that of the side wall 332 of the tray part 330, so that aring shaped space 336 is formed as a gas passage between the side walls332 and 334. The space 336 is connected to the horizontal andlongitudinal through holes 334 formed at the base part.

The argon gas supplied by (not shown) a gas supplying apparatus may flowinto the ring shaped space 336 between the side walls 332 and 334through the hole 335 and through holes 334 formed at the base part andthe residual gas in the inner space of the tray part may be dischargedvia the same gas flowing paths mentioned above.

In this embodiment, the tray part and the base part are integrate in onepiece, where the hole 335 and through holes 334 are formed at the basepart 331 for the gas inflow and discharging and the stepped surface 333of the base part is formed at the base part 331 for mounting thesintering chamber 340, so that the sintering device may be compacted invirtue of the decrease of the number of parts and the manufacturing costmay be decreased. Accordingly, the sintering device according to theinvention is improved as compared with the prior sintering device inwhich the tray and the base plate are separated, a spacer should beformed at the bottom for a space as a gas passage.

Referring to FIG. 6, the sintering device according to the variantembodiment of the invention includes a cylindrical member 250 providedbetween the side wall of the tray part 330 and the side wall of thesintering chamber 340 for the prevention of oxidization. The cylindricalmember 250 has a diameter which is bigger than that of tray part andsmaller than that of the sintering chamber, so that the cylinder membermay be arranged on the base part 331 and between the side walls of thetray part and sintering chamber. At this time, it is desirable that thecylinder member is separated from the side wall of the tray part 330 notto prevent the inflow and discharging of the gas.

Accordingly, the argon gas supplied by the gas supplying apparatus maybe flowed in the space 336 between the side walls 332 and 334 throughthe hole 335 and flows in the inner space of the tray part 330, therebyurging the residual gas in the inner space of the tray part to bedischarged and the argon atmosphere is formed in the inner space of thetray part. Therefore, in the sintering operation, the oxygen remained inthe space 336 may be first contacted with the cylindrical member 250 andthe oxidation of the metallic workpiece may be prevented.

The cylindrical member 250 is preferably formed in a sheet made fromtitanium or titanium allow and is first oxidized by the residual oxygenin the space 336 to prevent from the metallic workpiece to oxidation.Accordingly, the quality of the sintered workpiece may be improved.

The forgoing embodiments are merely exemplary and are not to beconstrued as limiting the present invention. The present teachings canbe readily applied to other types of apparatuses. The description of thepresent invention is intended to be illustrative, and not to limit thescope of the claims. Many alternatives, modifications, and variationswill be apparent to those skilled in the art.

What is claimed is:
 1. A sintering device comprising a tray including atray part in which metallic workpieces to be sintered (not representedhere) are placed during the sintering operation and a base part in whichthe tray is located including gas-flowing holes and side wall extendedupwardly from the edge of the upper surface of the base part, and asintering chamber including side wall extended downwardly from the uppersurface for covering the tray part and at least one gas flow passagebetween the inner surface thereof and outer surface of the side wall ofthe tray part; wherein the tray part and base part are integrallyformed; wherein the base part includes at the lower portion throughholes in horizontal and longitudinal directions for gas inflowing anddischarging, a hole at crossover point of the through holes forpenetrating the center portion of the base plate and extended to theexterior, and wherein the lower end of the sinter chamber is disposed onthe lowered and stepped surface of the base part and the stepped portionformed in the middle of the side wall of the sintering chamber issupported by the upper end of the side wall of the tray for allowing thegas to flow.
 2. The sintering device as claimed in claim 1, wherein acylindrical member for the prevention of oxidization is disposed on thebase part between the side walls of the tray part and sintering chamberto prevent the oxygen contacting the metallic workpiece.
 3. Thesintering device as claimed in claim 2, wherein the cylindrical memberis formed in a sheet made from titanium or titanium allow.
 4. Thesintering device as claimed in claim 1, wherein the inner diameter ofthe sidewall of the sintering chamber is bigger than the outer diameterof the side wall of the tray part to form a cylindrical space as a gasflow passage between the side walls of the tray part and sinteringchamber, and the cylindrical space is communicated with the throughholes in horizontal and longitudinal directions formed at the base part.